# NSProtocolChecker class reference

Generated at 2025-02-13 06:02:40 +0000
1995 Free Software Foundation, Inc.
Software documentation for the NSProtocolChecker class
Foundation/NSProtocolChecker.h
The NSProtocolChecker and NSProxy classes provide message filtering and forwarding capabilities. If you wish to ensure at runtime that a given object will only be sent messages in a certain protocol, you create an `NSProtocolChecker` instance with the protocol and the object as arguments- id versatileObject = [[ClassWithManyMethods alloc] init]; id narrowObject = [NSProtocolChecker protocolCheckerWithTarget: versatileObject protocol: @protocol(SomeSpecificProtocol)]; return narrowObject; This is often used in conjunction with distributed objects to expose only a subset of an objects methods to remote processes
protocolCheckerWithTarget:
anObject
protocol:
aProtocol
Allocates and initializes an NSProtocolChecker instance by calling -initWithTarget:protocol:
Autoreleases and returns the new instance.
forwardInvocation:
anInvocation
Forwards any message to the delegate if the method is declared in the checker's protocol; otherwise raises an `NSInvalidArgumentException`.
initWithTarget:
anObject
protocol:
aProtocol
Initializes a newly allocated NSProtocolChecker instance that will forward any messages in the aProtocol protocol to anObject, its delegate. Thus, the checker can be vended in lieu of anObject to restrict the messages that can be sent to anObject. If any method in the protocol returns anObject, the checker will replace the returned value with itself rather than the target object.
Returns the new instance.
protocol
Returns the protocol object the checker uses to verify whether a given message should be forwarded to its delegate.
target
Returns the target of the NSProtocolChecker.